diff options
Diffstat (limited to 'system/xen/xsa/xsa335-qemu.patch')
| -rw-r--r-- | system/xen/xsa/xsa335-qemu.patch | 84 |
1 files changed, 84 insertions, 0 deletions
diff --git a/system/xen/xsa/xsa335-qemu.patch b/system/xen/xsa/xsa335-qemu.patch new file mode 100644 index 0000000000..5617502359 --- /dev/null +++ b/system/xen/xsa/xsa335-qemu.patch @@ -0,0 +1,84 @@ +From c5bd2924c6d6a5bcbffb8b5e7798a88970131c07 Mon Sep 17 00:00:00 2001 +From: Gerd Hoffmann <kraxel@redhat.com> +Date: Mon, 17 Aug 2020 08:34:22 +0200 +Subject: [PATCH] usb: fix setup_len init (CVE-2020-14364) + +Store calculated setup_len in a local variable, verify it, and only +write it to the struct (USBDevice->setup_len) in case it passed the +sanity checks. + +This prevents other code (do_token_{in,out} functions specifically) +from working with invalid USBDevice->setup_len values and overrunning +the USBDevice->setup_buf[] buffer. + +Fixes: CVE-2020-14364 +Signed-off-by: Gerd Hoffmann <kraxel@redhat.com> +--- + hw/usb/core.c | 16 ++++++++++------ + 1 file changed, 10 insertions(+), 6 deletions(-) + +diff --git a/hw/usb/core.c b/hw/usb/core.c +index 5abd128b6bc5..5234dcc73fea 100644 +--- a/hw/usb/core.c ++++ b/hw/usb/core.c +@@ -129,6 +129,7 @@ void usb_wakeup(USBEndpoint *ep, unsigned int stream) + static void do_token_setup(USBDevice *s, USBPacket *p) + { + int request, value, index; ++ unsigned int setup_len; + + if (p->iov.size != 8) { + p->status = USB_RET_STALL; +@@ -138,14 +139,15 @@ static void do_token_setup(USBDevice *s, USBPacket *p) + usb_packet_copy(p, s->setup_buf, p->iov.size); + s->setup_index = 0; + p->actual_length = 0; +- s->setup_len = (s->setup_buf[7] << 8) | s->setup_buf[6]; +- if (s->setup_len > sizeof(s->data_buf)) { ++ setup_len = (s->setup_buf[7] << 8) | s->setup_buf[6]; ++ if (setup_len > sizeof(s->data_buf)) { + fprintf(stderr, + "usb_generic_handle_packet: ctrl buffer too small (%d > %zu)\n", +- s->setup_len, sizeof(s->data_buf)); ++ setup_len, sizeof(s->data_buf)); + p->status = USB_RET_STALL; + return; + } ++ s->setup_len = setup_len; + + request = (s->setup_buf[0] << 8) | s->setup_buf[1]; + value = (s->setup_buf[3] << 8) | s->setup_buf[2]; +@@ -259,26 +261,28 @@ static void do_token_out(USBDevice *s, USBPacket *p) + static void do_parameter(USBDevice *s, USBPacket *p) + { + int i, request, value, index; ++ unsigned int setup_len; + + for (i = 0; i < 8; i++) { + s->setup_buf[i] = p->parameter >> (i*8); + } + + s->setup_state = SETUP_STATE_PARAM; +- s->setup_len = (s->setup_buf[7] << 8) | s->setup_buf[6]; + s->setup_index = 0; + + request = (s->setup_buf[0] << 8) | s->setup_buf[1]; + value = (s->setup_buf[3] << 8) | s->setup_buf[2]; + index = (s->setup_buf[5] << 8) | s->setup_buf[4]; + +- if (s->setup_len > sizeof(s->data_buf)) { ++ setup_len = (s->setup_buf[7] << 8) | s->setup_buf[6]; ++ if (setup_len > sizeof(s->data_buf)) { + fprintf(stderr, + "usb_generic_handle_packet: ctrl buffer too small (%d > %zu)\n", +- s->setup_len, sizeof(s->data_buf)); ++ setup_len, sizeof(s->data_buf)); + p->status = USB_RET_STALL; + return; + } ++ s->setup_len = setup_len; + + if (p->pid == USB_TOKEN_OUT) { + usb_packet_copy(p, s->data_buf, s->setup_len); +-- +2.18.4 |